‘Fortnum and Mason’s is surrounded by police as this is a crime scene. Persons responsible will be arrested’: a message sent out by the Metropolitan Police text service for protesters at 18.33, just as I was getting home from Saturday’s TUC march. The slogan was ‘March for the alternative!’ – ‘what sort of alternative?’ Evan Davis asked on the Today programme that morning – but UK Uncut’s flyers encouraged us to ‘occupy for the alternative’. Fortnum’s was targeted because its owners, Whittington Investments, ‘have dodged over £40 million in tax’. Inside, ‘this has basically turned into a giant picnic,’ Laurie Penny tweeted, apart from the moment a display of chocolate bunnies was knocked over and had to be put painstakingly back together. Pictures and videos show protesters sitting on the floor, nestled between the glass cabinets and wooden counters or gathered behind brass railings, singing. The occupiers were arrested: of 149 charged by police on Saturday, 138 were done for ‘aggravated trespass’ or sitting on Fortnum’s carpet for a few hours. Even Fortnum’s have admitted that ‘the damage is minimal.’

UK Uncut’s actions – a school sports day in Topshop, read-ins at Barclay’s banks, sit-ins at Vodafone shops – have won a fair amount of attention as creative, non-violent civil disobedience. But in yesterday’s right-wing papers, UK Uncut was indistinguishable from the ‘black bloc’ who attacked some of UK Uncut’s targets (Topshop, the banks) as well as some of their own (the Ritz, De Beers) with paint, fireworks and makeshift battering rams. The black of their jeans and hoodies inspired jackboot headlines: ‘Ritzkrieg’ in the Mail, ‘Blitz on the Ritz’ in the News of the World. The pictures in the Mail showed ‘Tory Scum’ written on the red brick in spearmint spraypaint and a girl with red hair apparently taunting the crowd. The separate actions of UK Uncut and the black bloc have, perhaps conveniently for the government, overshadowed the main event. But in response they point to the ineffectiveness of the Stop the War march in 2003, a peaceful and orderly protest by hundreds of thousands of people that achieved nothing.

The SWP had hung their banners by the time I got to Trafalgar Square and found a spot behind the NASUWT, the PCS and a homemade sign that asked: ‘Can I live in your duckhouse?’ There were babies in prams (pinned to one pushchair: ‘This government stinks worse than my nappies’); children with flags, tabards and horns, competing with the sound of the helicopters overhead; people in wheelchairs being filmed by journalists; dogs in blankets with union insignia; old couples; families with grown-up children; observers from Liberty in fluorescent green tabards, TUC stewards in pink, police in yellow. Everyone was taking photos.

As we moved on to Piccadilly there was more to take photos of than each other. Shops and cafés were splattered with coloured paint bombs, as if they were starring in one of those paint explosion adverts for Sony TVs, if you ignored the smashed windows. Pret was untouched – full of hungry marchers, it seemed – and so was The Wolseley, the uniformed doorman defiant. The Burlington Arcade’s guards, in gold braid, had shut themselves behind their gold-tipped gates.

When I got to Hyde Park the screens were showing a hairdressing student talking about how the loss of the EMA would affect her, and the alternative was announced: a Robin Hood tax and a clamp down on tax avoidance. There was a Brazilian carnival band, and dancers in feather headdresses and sequinned bikinis. A girl wore a very serious face to be photographed for the papers holding her homemade ‘I ♥ books’ sign, giggling once it was over.

Lots of the marchers went home along Oxford Street, getting more and more diluted with the shoppers until even someone in an NASUWT tabard was looking at shoes in the Camper shop. We’d become our old selves so much that it was almost a shock to see a bonfire in the centre of Oxford Circus and Topshop guarded by a thick cordon of riot police. It had been splattered with pastels: lilac, caramel, pink, mint, bluebell; an echo of the primary coloured spraypaint that had been used to mark future roadworks on the tarmac.

The fires continued until 2 a.m. in Trafalgar Square: police charged in to defend the faulty Olympic countdown clock and the last protesters retreated to Nelson’s Column. The next morning Vince Cable told BBC One’s Politics Show: ‘We’re not going to change the basic economic strategy… No government – coalition, Labour or any other – would change its fundamental economic policy simply in response to a demonstration of that kind.’ And that, or so the government hopes, was that.

I fear the police used the arrests at F&M to get a full list of names and addresses of the UKUncut brigade. Grass-roots protest organisations that spring up from nowhere while engaging in aggravated satire make the authorities nervous.

Blanket charges of criminal damage and aggravated trespass was just for deterrent value. Most of the criminal damage charges have already been dropped. The police want all those clean-cut university kids to think of their c.v.s before opening another library in Boots. Welcome to the show, kids.

I think the truth is probably more mundane. The Guardian says that a total of 201 people were arrested in connection to (all of ) the protests on Saturday. The 138 in Fortnum and Mason helpfully made up the numbers, deflecting attention from the fact that the police have little clue about who was smashing shop windows or chucking glass bottles at them. Unfortunate for those 138, but unlikely to be any massive conspiracy — you shouldn’t credit them with too much competence.

I think it’s worth making the point that the whole march had the feel of a friendly, inclusive, happy, funny event (typical slogan: “the banks ain’t broke; let’s fix them anyway”) and it wasn’t until I got home that I learned that there had been violence elsewhere. Personally, I find it hard to see, as some have done, masked macho males in black smashing objects as the cutting edge of the new progressive politics but maybe that’s just me.

I’m very doubtful about the motives of those ‘masked macho males’. Could it be that we have had a rerun of that hoary trick of using a few police ‘off-duty’ to cause some fisticuffs? Isn’t this what happened at that last demo?